Catheter with measurement electrodes

Abstract

A catheter is provided which comprises a tubular body that defines a passage therewithin terminating in an axially-facing opening at the tip end of the catheter, the opening serving as a sampling port. A pair of annular electrodes are arranged in spaced relationship around the sampling port on the rim of the open end and are connected to suitable measuring equipment.

What is claimed is: 
     
       1. A catheter comprising a tubular body which defines therewithin a passage which extends to an axially-facing open end of the tubular body and which serves as a sampling port at the tip of the catheter, said catheter further comprising first and second annular electrodes which are arranged in spaced relationship on the rim of the said open end around the sampling port, and electrical connection means for connecting said first and second electrodes to measuring equipment. 
     
     
       2. A catheter as claimed in claim 1, wherein an end portion of the tubular body which includes the tip of the catheter comprises poly vinyl chloride. 
     
     
       3. A catheter as claimed in claim 1, wherein the said first and second annular electrodes are vacuum deposited on the said rim. 
     
     
       4. A catheter as claimed in claim 1, wherein the said electrodes comprise silver. 
     
     
       5. A catheter as claimed in claim 1, wherein the tubular body comprises a main elongate tubular part and tubular end portion secured to said tubular part, said tubular end portion including the tip of the catheter. 
     
     
       6. A catheter as claimed in claim 5, wherein part of the said tubular end portion fits coaxially within an end portion of the said main elongate tubular part. 
     
     
       7. A catheter as claimed in claim 1, wherein the said rim, including the first and second annular electrodes, is covered by a gas diffusion membrane. 
     
     
       8. A catheter as claimed in claim 1, wherein the said rim, including the first and second annular electrodes, is covered by an electrolytic material.